Research On Freeform Feature And Constraint Solving Feature-Based Modeing

Feature modeling is one of the most important technologies in the integrated system of CAD or CAM, which is the key problem in product model design. To construct a product information model based on the unified features, the data exchange and share can be solved basically during the process of the product design, producing, quality control and management. However, the current feature modeling technologies are mostly based on the regular-shape features. With the development of feature modeling technologies, more and more freeform features are involved, this question needs to be solved timely. This paper mainly discusses the freeform feature design based on the feature modeling and its constraint solving. The purpose is to introduce freeform feature in current feature modeling technologies, and users can create instances with a set of parameters in the freeform feature modeling. In order to purchase this purpose, the paper makes a systematic analysis on freeform feature based on the study of the HUST-CAID system (Computer Aided Industry Design System developed by Harbin University of Science and Technology). As its shape domain limits to the prismatic and cylindrical shapes in the HUST-CAID system, the freeform feature modeling is introduced in it. Classification and parameters are defined combining with the HUST-CAID; users can intuitively design any curved surface using a set of suitable parameters provided by the system without concerning the lower layer design. If users want to modify the parameters, the system will correspondingly provide feedback automatically. In order to obtain the right graphics agree with the constraint, it is provided a new novel prototype-driven constraint solving algorithm. The simulation result shows that this novel algorithm simplified constraint solving and feature modeling greatly, and the HUST-CAID system is more perfect and more practical because of the introduction of the freeform feature.